Frequently Asked Questions about OWTS

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The information on this page was prepared by Environmental Health and responds to the most frequently asked questions at the first meeting of the Environmental Health Task Force.

The San Lorenzo River Watershed has the highest septic system density of any comparable area in the State. While bacteria levels in the River have declined in the last few years from the dangerously high levels which prevailed in the 1980s, in many areas bacteria levels just barely meet the standards for safe swimming. Nitrate levels remain at levels 5-7 times higher than natural levels and pose a threat to the drinking water supply for approximately 85,000 of the County's residents. Continued improvements to septic systems are needed to further reduce contaminant levels in the River.

Septic tanks are regulated locally by the County Health Officer through the Environmental Health Division of the Health Services Agency in accordance with standards established by the State Regional Water Quality Control Board. The standards and regulations for septic tanks in the San Lorenzo Valley are contained in the Wastewater Management Plan for the San Lorenzo River Watershed and the San Lorenzo Nitrate Management Plan. The plans were approved by the Regional Water Quality Control Board and the Santa Cruz County Board of Supervisors in 1995. The standards and regulations contained in these documents may not be changed without the consent of the both the Board of Supervisors and the Regional Water Quality Control Board.

There have been no significant changes in County septic system standards since 1995. Most standards have been in place since at least 1993. Currently, there are no formal proposals for changing the current standards. However, during the past year, there have been some changes in the procedures for enforcing the standards which have caused some concern by septic contractors, realtors and property owners that the procedures may be unnecessarily complicated, strict, or burdensome. County staff are working with the public and interested parties to evaluate those concerns and to ensure that standards and procedures are friendly, workable, and effective in protecting public health and water quality.

No. The table below compares the annual cost for a single-family residence of a septic tank with the cost of sewer service in the City of Santa Cruz and within the County Sanitation District which provides sewer services for Live Oak, Capitola and Aptos.

Single Family Residence
A Comparison of Sewer Service and Septic Tanks Excluding Repairs
  Sewer Service San Lorenzo Valley - Typical
Item City of Santa Cruz Aptos, Capitola and Live Oak Standard Non-Standard Non-Standard Alternative Technology
Annual Inspection Charge NA NA $25.00 $115.00 $209.00
Annual Sewer Bills $258.00 $396.24 NA NA NA
Pumping - Typically ever 5 years NA NA $300.00 $300.00 $300.00

Over a five-year period, the owner of a single-family residence will incur the following costs:

  • City of Santa Cruz - $1,290 for sewer services
  • Aptos, Capitola or Live Oak - $1,980 for sewer services
  • San Lorenzo Valley
    Standard Septic System - $425 for inspection fees and pumping charges Non-Standard Septic System - $875 for inspection fees and pumping charges Non-Standard Alternative Technology System - $1,345 for inspection fees and pumping charges.

A Standard Septic System is a conventional onsite sewage disposal system which consists of a septic tank and leach field, which meet the current standards for tank size, leach field size, groundwater separation, setbacks from streams, cut banks, etc. The required size of the leach field for a residence is determined by the number of bedrooms and the soil type. There must also be adequate "expansion area" on the parcel to accommodate a standard replacement leach field which can be installed when the existing leach field fails. Under current standards, which have been in place since 1995, at least 90% of the 400 septic system repairs in the San Lorenzo River Watershed have met requirements for a Standard System. Parcels with Standard Systems are eligible for major building additions, provided standards can still be met after the remodel. (See specific standards in County Code Chapter 7.38 and in the Standards and Procedures for the Repair and Upgrade of Septic Systems.)

A Non-Standard System is a recently permitted septic system (since 1993) which either uses alternative technology or does not meet critical requirements for a standard conventional septic system, such as groundwater separation, leach field size, or availability of expansion area. Parcels with septic systems that do not meet standards are eligible for only minor building additions (a one-time addition of less than 500 square feet and no bedroom additions). Parcels with alternative systems such as mound systems, at-grade systems, sand filters, or treatment units may be eligible for major building additions.

Because most Non-Standard Systems require special operating conditions (such as water conservation or regular pumping) and additional maintenance and oversight to ensure they function properly, County staff inspect them on an annual basis and charge an annual fee on the tax bill of those systems that require inspection. (Annual fees are collected through CSA 12.) Prior to approval and installation of a Nonstandard System, the property owner signs an Acknowledgment of Nonstandard System which indicates that they recognize and accept the special operating conditions and limitations required for use of such a system.

As a result of obtaining a permit for installation and use of a Nonstandard System, a Notice of Nonstandard System is recorded on the deed to describe the type of system and the special operating conditions and limitations, such as water conservation or regular maintenance, necessary for the system to perform properly. The purpose of the Notice is to notify any prospective buyer of the special conditions and limitations, if any, of the sewage disposal system serving that property, so that a new buyer will not unwittingly buy a property on which the septic system conditions may limit their future use of the property. Although these are factors that should be fully disclosed in any real estate transaction, the Notice is written to provide complete and specific information.

Older existing septic systems installed prior to 1993 are not considered to be either Standard or Non-Standard. This designation only occurs at the time of septic system upgrade or replacement. It is estimated that at least 50-75% of the older existing systems in the County adequately meet current standards and would be eligible for approval of major remodels. It is also estimated that 95% of all existing systems could be upgraded to Standard Systems. The designation of a system as Nonstandard only occurs at the time of system upgrade when it is determined by private designers and County staff that the requirements for a standard system cannot be met.

For a parcel to be considered as having a Standard Septic System and be eligible for a major building addition, the parcel must have 100% expansion area. This means that there is adequate room on the parcel to install a replacement leach field that meets standards and is 100% of the size needed for the proposed number of bedrooms in the house.

For example, in loam soils without high groundwater, the area needed for a 100% expansion area for a three-bedroom house is about 50 feet by 20 feet, or 100 feet by 10 feet, depending on the configuration. The required area could be twice as large with higher groundwater or clay soils. The requirement for 100% expansion area helps to prevent the situation where a building addition may take up all the remaining area on the parcel, leaving no room to repair the septic system when it fails. In areas without sewers, having expansion area available helps ensure adequate ability to dispose of sewage for the lifetime of the home.